The sex of the four chicks, which hatched at the end of April, was identified by measuring the size of each chick's wing span and weight. The four new arrivals were then given unique rings by Sussex Ornithological Society (SOS), who originally set up the Cathedral's nestbox, to identify them in the future.
A tiny feather from each chick was also taken away for to identify each bird's unique DNA, records of which will be kept at the British History Museum.
Aren't birds brilliant! officer, Caroline Inglis, who witnessed the ringing last year, said: 'It was so exciting, I was on a real high. We were completely in their world, up at such a great height. The parents were flying low circling us, screaming and screeching. They made such an amazing noise, they were obviously petrified.'
'At one point the female landed and looked directly at me, I was eye to eye with a peregrine, it was completely breathtaking.'
'Looking at these fluffy little birds, you just can't believe they will turn into peregrines. As he rings them, Graham Roberts from SOS gives each chick an old glove to hold. It's mainly to stop them from scratching him, but they cling to it for dear life as a way of comforting themselves.'
From now until June 21, the RSPB Aren't birds brilliant! team will be at the Cathedral between 10am – 5pm, showing people amazing close up views of the peregrine chicks through a live nestcam.
The peregrines have nested in specially provided nest boxes at the Cathedral since 2002, raising a total of 22 young so far. The female bird always lays four eggs, which is the most a peregrine mother can produce.
The RSPB viewpoint can be found within the grounds of the Cloisters Café. A nest-side seat of the peregrines can also be found at http://www.rspb.org.uk/brilliant
Urban areas are now a great place to see peregrines. This is not the case in some national parks and nature spots where illegal persecution has seen numbers dwindle. The RSPB is currently campaigning to stamp out this practice and the illegal killing of all birds of prey. For more information visit www.rspb.org.uk/birdsofprey